Respond to application readiness — Build the smallest useful slice

PART I

Warm-up

Reconnect with a useful idea before starting respond to application readiness. In one or two sentences, describe the input, output or host boundary from the previous exercise that this lesson builds on. If you are arriving directly, skim the worked example first; there is no locked prerequisite.

A rough note is enough. You can revise it after the example.

PART II

Instruction & guided example

Build the smallest ready response

Readiness is a transition, not an import. An application declaration registers a response. Registration, delivery of app.ready, and execution of the response are separate moments. The supplied exercise host decides delivery timing and whether registration after readiness receives a replay. Never infer replay or exactly-once delivery from the callback syntax.

A kiosk host delivers app.ready once. The required response is to show the title Welcome. Loading an optional promotional image is a separate host operation whose availability is unknown.

Use an event ledger: time, delivered event, owner state, response, and visible state. A row that registers a callback has no delivered event. Mark the visible state unchanged until a host-delivered event authorizes the response. Worked case: The minimal acceptance trace is Starting → ready delivery → title Welcome. If the image is unavailable, the title still appears. The title requirement has no dependency on image success.

Compare the tempting alternative: Putting the title change after an unconditional image operation can leave a ready application labeled Starting when optional artwork fails.

Worked reasoning and supplied artifact

// Paper trace / supplied exercise-host contract; no execution claimed.
// A kiosk host delivers app.ready once. The required response is to show the title Welcome. Loading an optional promotional image is a separate host operation whose availability is unknown.
// The minimal acceptance trace is Starting → ready delivery → title Welcome. If the image is unavailable, the title still appears. The title requirement has no dependency on image success.

Illustrative example from the proposed WillowScript design. The language and WUIX/WMATH/WDB/WAUDIO/WTMP services are not implemented in the supplied source. This site has no interpreter, VM or native host and does not execute or certify the snippet.

Try the guided change

Reconstruct the supplied worked case first: list its inputs, intermediate decisions and final artifact. Compare each row with the explanation and identify exactly where the rejected alternative fails. Then use the changed inputs in Part IV for independent work.

• Write the supplied inputs and initial state before following the example.
• Reconstruct each intermediate calculation or host decision, then compare with the worked artifact.
• Explain why the contrasting alternative fails before attempting the changed inputs in Part IV.

PART III

Take a breather

Step back after the guided example. Look away from the screen, stretch, or reread your prediction. This is an optional learning pause, not a timer or an assessment gate.

When you return, try to name the lesson’s key idea without copying its wording. If that feels difficult, return to Part II and trace one line rather than restarting the entire lesson.

PART IV

Independent practice

Project context: Support request workflow. Build a small, understandable change around respond to application readiness.

Specify the minimal callback responsibility in words or source-backed configuration, then give ready-with-image and ready-without-image predictions.

What to produce

A callback contract and two acceptance rows identifying the optional effect.

• State the intended behavior in a sentence before editing.
• Use only source-backed syntax and the host services whose contract you have been given.
• Record a normal case and a boundary or unavailable-resource case.
• Label hand predictions separately from anything actually measured in a supplied toolchain.

Syntax colors are a reading aid, not a compiler. The line you are editing stays uncolored until you move to a different line; capitalization is never changed. Drafts stay on this browser and code is not executed.

import wuix.widget;
import app;
domain Workspace {
    const application = Application({
        name: "Workspace",
        window: { title: "Dashboard", size: [1280, 800] },
        events: {
            "app.ready": fnc() -> void { console.log("Ready"); }
        }
    });
}

PART V

Self-check

Use this check to notice what to revisit. It does not award a private course grade, block another page or claim to verify compiled code. Every answer has a learning explanation.

You may keep exploring even if you are unsure. Use the hint, compare the trace, and revise your explanation.

PART VI

Recap & small task

Bring the idea back to the mod feature you are building. A useful recap connects the mechanism to a decision you can make in your own code.

• Build the smallest ready response
• Specify the minimal callback responsibility in words or source-backed configuration, then give ready-with-image and ready-without-image predictions.
• Separate source-backed behavior, host requirements and untested predictions.

One small recap task

Remove one unnecessary dependency from your proposed response.

This marks your personal practice record only. It is not a certification or an official workspace assessment.